1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware 4 * monitoring 5 * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23 6 * based on lm75.c by Frodo Looijaard <frodol@dds.nl> 7 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 8 * the help of Jean Delvare <jdelvare@suse.de> 9 * 10 * The DS1621 device is a digital temperature/thermometer with 9-bit 11 * resolution, a thermal alarm output (Tout), and user-defined minimum 12 * and maximum temperature thresholds (TH and TL). 13 * 14 * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621 15 * and similar in operation, with slight variations as noted in the device 16 * datasheets (please refer to www.maximintegrated.com for specific 17 * device information). 18 * 19 * Since the DS1621 was the first chipset supported by this driver, 20 * most comments will refer to this chipset, but are actually general 21 * and concern all supported chipsets, unless mentioned otherwise. 22 */ 23 24 #include <linux/module.h> 25 #include <linux/init.h> 26 #include <linux/slab.h> 27 #include <linux/jiffies.h> 28 #include <linux/i2c.h> 29 #include <linux/hwmon.h> 30 #include <linux/hwmon-sysfs.h> 31 #include <linux/err.h> 32 #include <linux/mutex.h> 33 #include <linux/sysfs.h> 34 #include <linux/kernel.h> 35 36 /* Supported devices */ 37 enum chips { ds1621, ds1625, ds1631, ds1721, ds1731 }; 38 39 /* Insmod parameters */ 40 static int polarity = -1; 41 module_param(polarity, int, 0); 42 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 43 44 /* 45 * The Configuration/Status register 46 * 47 * - DS1621: 48 * 7 6 5 4 3 2 1 0 49 * |Done|THF |TLF |NVB | X | X |POL |1SHOT| 50 * 51 * - DS1625: 52 * 7 6 5 4 3 2 1 0 53 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| 54 * 55 * - DS1631, DS1731: 56 * 7 6 5 4 3 2 1 0 57 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT| 58 * 59 * - DS1721: 60 * 7 6 5 4 3 2 1 0 61 * |Done| X | X | U | R1 | R0 |POL |1SHOT| 62 * 63 * Where: 64 * - 'X' is Reserved 65 * - 'U' is Undefined 66 */ 67 #define DS1621_REG_CONFIG_NVB 0x10 68 #define DS1621_REG_CONFIG_RESOL 0x0C 69 #define DS1621_REG_CONFIG_POLARITY 0x02 70 #define DS1621_REG_CONFIG_1SHOT 0x01 71 #define DS1621_REG_CONFIG_DONE 0x80 72 73 #define DS1621_REG_CONFIG_RESOL_SHIFT 2 74 75 /* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */ 76 static const unsigned short ds1721_convrates[] = { 77 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */ 78 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */ 79 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */ 80 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */ 81 }; 82 83 #define DS1621_CONVERSION_MAX 750 84 #define DS1625_CONVERSION_MAX 500 85 86 #define DS1621_TEMP_MAX 125000 87 #define DS1621_TEMP_MIN (-55000) 88 89 /* The DS1621 temperature registers */ 90 static const u8 DS1621_REG_TEMP[3] = { 91 0xAA, /* input, word, RO */ 92 0xA2, /* min, word, RW */ 93 0xA1, /* max, word, RW */ 94 }; 95 #define DS1621_REG_CONF 0xAC /* byte, RW */ 96 #define DS1621_COM_START 0xEE /* no data */ 97 #define DS1721_COM_START 0x51 /* no data */ 98 #define DS1621_COM_STOP 0x22 /* no data */ 99 100 /* The DS1621 configuration register */ 101 #define DS1621_ALARM_TEMP_HIGH 0x40 102 #define DS1621_ALARM_TEMP_LOW 0x20 103 104 /* Conversions */ 105 #define ALARMS_FROM_REG(val) ((val) & \ 106 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 107 108 /* Each client has this additional data */ 109 struct ds1621_data { 110 struct i2c_client *client; 111 struct mutex update_lock; 112 bool valid; /* true if following fields are valid */ 113 unsigned long last_updated; /* In jiffies */ 114 enum chips kind; /* device type */ 115 116 u16 temp[3]; /* Register values, word */ 117 u8 conf; /* Register encoding, combined */ 118 u8 zbits; /* Resolution encoded as number of 119 * zero bits */ 120 u16 update_interval; /* Conversion rate in milliseconds */ 121 }; 122 123 static inline int DS1621_TEMP_FROM_REG(u16 reg) 124 { 125 return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10); 126 } 127 128 /* 129 * TEMP: 0.001C/bit (-55C to +125C) 130 * REG: 131 * - 1621, 1625: 0.5C/bit, 7 zero-bits 132 * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits 133 */ 134 static inline u16 DS1621_TEMP_TO_REG(long temp, u8 zbits) 135 { 136 temp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX); 137 temp = DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits; 138 return temp; 139 } 140 141 static void ds1621_init_client(struct ds1621_data *data, 142 struct i2c_client *client) 143 { 144 u8 conf, new_conf, sreg, resol; 145 146 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 147 /* switch to continuous conversion mode */ 148 new_conf &= ~DS1621_REG_CONFIG_1SHOT; 149 150 /* setup output polarity */ 151 if (polarity == 0) 152 new_conf &= ~DS1621_REG_CONFIG_POLARITY; 153 else if (polarity == 1) 154 new_conf |= DS1621_REG_CONFIG_POLARITY; 155 156 if (conf != new_conf) 157 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); 158 159 switch (data->kind) { 160 case ds1625: 161 data->update_interval = DS1625_CONVERSION_MAX; 162 data->zbits = 7; 163 sreg = DS1621_COM_START; 164 break; 165 case ds1631: 166 case ds1721: 167 case ds1731: 168 resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> 169 DS1621_REG_CONFIG_RESOL_SHIFT; 170 data->update_interval = ds1721_convrates[resol]; 171 data->zbits = 7 - resol; 172 sreg = DS1721_COM_START; 173 break; 174 default: 175 data->update_interval = DS1621_CONVERSION_MAX; 176 data->zbits = 7; 177 sreg = DS1621_COM_START; 178 break; 179 } 180 181 /* start conversion */ 182 i2c_smbus_write_byte(client, sreg); 183 } 184 185 static struct ds1621_data *ds1621_update_client(struct device *dev) 186 { 187 struct ds1621_data *data = dev_get_drvdata(dev); 188 struct i2c_client *client = data->client; 189 u8 new_conf; 190 191 mutex_lock(&data->update_lock); 192 193 if (time_after(jiffies, data->last_updated + data->update_interval) || 194 !data->valid) { 195 int i; 196 197 dev_dbg(&client->dev, "Starting ds1621 update\n"); 198 199 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 200 201 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 202 data->temp[i] = i2c_smbus_read_word_swapped(client, 203 DS1621_REG_TEMP[i]); 204 205 /* reset alarms if necessary */ 206 new_conf = data->conf; 207 if (data->temp[0] > data->temp[1]) /* input > min */ 208 new_conf &= ~DS1621_ALARM_TEMP_LOW; 209 if (data->temp[0] < data->temp[2]) /* input < max */ 210 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 211 if (data->conf != new_conf) 212 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, 213 new_conf); 214 215 data->last_updated = jiffies; 216 data->valid = true; 217 } 218 219 mutex_unlock(&data->update_lock); 220 221 return data; 222 } 223 224 static ssize_t temp_show(struct device *dev, struct device_attribute *da, 225 char *buf) 226 { 227 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 228 struct ds1621_data *data = ds1621_update_client(dev); 229 return sprintf(buf, "%d\n", 230 DS1621_TEMP_FROM_REG(data->temp[attr->index])); 231 } 232 233 static ssize_t temp_store(struct device *dev, struct device_attribute *da, 234 const char *buf, size_t count) 235 { 236 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 237 struct ds1621_data *data = dev_get_drvdata(dev); 238 long val; 239 int err; 240 241 err = kstrtol(buf, 10, &val); 242 if (err) 243 return err; 244 245 mutex_lock(&data->update_lock); 246 data->temp[attr->index] = DS1621_TEMP_TO_REG(val, data->zbits); 247 i2c_smbus_write_word_swapped(data->client, DS1621_REG_TEMP[attr->index], 248 data->temp[attr->index]); 249 mutex_unlock(&data->update_lock); 250 return count; 251 } 252 253 static ssize_t alarms_show(struct device *dev, struct device_attribute *da, 254 char *buf) 255 { 256 struct ds1621_data *data = ds1621_update_client(dev); 257 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 258 } 259 260 static ssize_t alarm_show(struct device *dev, struct device_attribute *da, 261 char *buf) 262 { 263 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 264 struct ds1621_data *data = ds1621_update_client(dev); 265 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 266 } 267 268 static ssize_t update_interval_show(struct device *dev, 269 struct device_attribute *da, char *buf) 270 { 271 struct ds1621_data *data = dev_get_drvdata(dev); 272 return sysfs_emit(buf, "%hu\n", data->update_interval); 273 } 274 275 static ssize_t update_interval_store(struct device *dev, 276 struct device_attribute *da, 277 const char *buf, size_t count) 278 { 279 struct ds1621_data *data = dev_get_drvdata(dev); 280 struct i2c_client *client = data->client; 281 unsigned long convrate; 282 s32 err; 283 int resol = 0; 284 285 err = kstrtoul(buf, 10, &convrate); 286 if (err) 287 return err; 288 289 /* Convert rate into resolution bits */ 290 while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) && 291 convrate > ds1721_convrates[resol]) 292 resol++; 293 294 mutex_lock(&data->update_lock); 295 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 296 data->conf &= ~DS1621_REG_CONFIG_RESOL; 297 data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT); 298 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf); 299 data->update_interval = ds1721_convrates[resol]; 300 data->zbits = 7 - resol; 301 mutex_unlock(&data->update_lock); 302 303 return count; 304 } 305 306 static DEVICE_ATTR_RO(alarms); 307 static DEVICE_ATTR_RW(update_interval); 308 309 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0); 310 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1); 311 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2); 312 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS1621_ALARM_TEMP_LOW); 313 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS1621_ALARM_TEMP_HIGH); 314 315 static struct attribute *ds1621_attributes[] = { 316 &sensor_dev_attr_temp1_input.dev_attr.attr, 317 &sensor_dev_attr_temp1_min.dev_attr.attr, 318 &sensor_dev_attr_temp1_max.dev_attr.attr, 319 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 320 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 321 &dev_attr_alarms.attr, 322 &dev_attr_update_interval.attr, 323 NULL 324 }; 325 326 static umode_t ds1621_attribute_visible(struct kobject *kobj, 327 struct attribute *attr, int index) 328 { 329 struct device *dev = kobj_to_dev(kobj); 330 struct ds1621_data *data = dev_get_drvdata(dev); 331 332 if (attr == &dev_attr_update_interval.attr) 333 if (data->kind == ds1621 || data->kind == ds1625) 334 /* shhh, we're hiding update_interval */ 335 return 0; 336 return attr->mode; 337 } 338 339 static const struct attribute_group ds1621_group = { 340 .attrs = ds1621_attributes, 341 .is_visible = ds1621_attribute_visible 342 }; 343 __ATTRIBUTE_GROUPS(ds1621); 344 345 static const struct i2c_device_id ds1621_id[]; 346 347 static int ds1621_probe(struct i2c_client *client) 348 { 349 struct ds1621_data *data; 350 struct device *hwmon_dev; 351 352 data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data), 353 GFP_KERNEL); 354 if (!data) 355 return -ENOMEM; 356 357 mutex_init(&data->update_lock); 358 359 data->kind = i2c_match_id(ds1621_id, client)->driver_data; 360 data->client = client; 361 362 /* Initialize the DS1621 chip */ 363 ds1621_init_client(data, client); 364 365 hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev, 366 client->name, data, 367 ds1621_groups); 368 return PTR_ERR_OR_ZERO(hwmon_dev); 369 } 370 371 static const struct i2c_device_id ds1621_id[] = { 372 { "ds1621", ds1621 }, 373 { "ds1625", ds1625 }, 374 { "ds1631", ds1631 }, 375 { "ds1721", ds1721 }, 376 { "ds1731", ds1731 }, 377 { } 378 }; 379 MODULE_DEVICE_TABLE(i2c, ds1621_id); 380 381 /* This is the driver that will be inserted */ 382 static struct i2c_driver ds1621_driver = { 383 .class = I2C_CLASS_HWMON, 384 .driver = { 385 .name = "ds1621", 386 }, 387 .probe = ds1621_probe, 388 .id_table = ds1621_id, 389 }; 390 391 module_i2c_driver(ds1621_driver); 392 393 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 394 MODULE_DESCRIPTION("DS1621 driver"); 395 MODULE_LICENSE("GPL"); 396